Mold for pneumatic-tire casings.



A. W. PINLAYSON.

MOLD FOB PNEUMATIC TIRE GASINGYS.

APPLICATION FILED JULY 21, 1913.

1,132,250, Patented Mar. 16, 1915.

2 SHEETS-SHEET 1.

Iitnrsara Jmmutnr 97/. g in Whmmimn I? mum" I7 I J ,7 I19 uuuu u n o JJnnrmur A. W. PI-NLAYSON.

MOLD FOB. PNEUMATIC TIRE GASINGS APPLICATION FILED JULY 21, 1913.

191.3Q25D Patented Mar. 16, 1915.

2 SHEETS-SHEET 2.

' "I 'IV l st 9 7,5 2 l9/5J 7 .9 nu |||||||||||m'' El f TED STATESPATENT ALEXANDL'ER W. FINLAYSON, DETROIT, MICHIGAN, ASSIGNOR TO F. S.STOEPEL AND CLAUD D. DOYLE, TRUSTEES.

MOLD FOR PNEUMATIC-TIRE CASINGS.

Specification of Letters Patent.

Patented Mar. 16, 1915.

. plication filed July 21, 1913. Serial No. 780,123.

To all whom it may concern:

Be it known that I, ALEXANDER W. FIN- LAYSON, a citizen of the UnitedStates, residing at Detroit, in the county of Wayne, State of Michigan,have invented certain new and useful Improvements. in Molds forPneumatic-Tire. Casings; and I do declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame, refer ence being had to the accompanying drawings, and to thecharacters of reference marked thereon, which form a part of thisspecification.

This invention relates to improvements in molds for pneumatic tirecasings, and relates particularly to a mold for forming and curingthetread of the casing wherein the Wearing surface is provided with raisedprojections to assist in gaining traction and to prevent slipping andskidding, commonly known as non-sln'dding treads.

The object of the invention is to provide means to facilitate theforming and curing of the non-skidding-surfaces of pneumatic tirecasings, in which this portion of the casing may be formed and curedtogether with. the body of the casing in a single operation ortreatment.

Heretofore it has been the common practice to form and cure the body ofthe casing and to then form and apply the raised tread surface,requiring a second treatment for the curing of thisportion of the tire,this being necessary owing to the difficulty in releasing the casingfrom the mold because of the locking tendency of the projecting surfaceof the tread. It has thereforebeen necessary to treat the casing bybinding the raised tread portion thereto with strips of cloth to holdthe tread surface in contact with the casing when subjected to theheattreatment for the final cur g. The mold herein 5 described is calculateto dispense with this second operation and to provide for the completecuring of the casing within the mold in a single operation.

The above object is attained by the construction illustrated in theaccompanying drawings, in .which Figure 1 is a plan view of the moldhaving the. upper plate removed and showing the interior of the mold inthe closed or contracted position. Fig. 2 is an edge eleposition.

Referring to the characters of reference.

1 represents the base plate of the mold which i is circular in form andhas extended from its upper face at the periphery of the mold an annularflange 2. Lying upon the upper face of the mold concentric therewith,and embraced by the flange 2, is a ring 3, said ring having formed inits inner perimeter a series of ratchet-shaped teeth or shoulders 4, thebody portion of which stand eccentric to the axis of the ring, and lyingwithin the ring 3 concentric with the mold is a divided ring composed ofsections 5 having a series of teeth or shoulders 4 formed in theperiphery thereof that engage and mesh with the shoulders at of the ring3, as clearly shown in Fig. 3. The sections 5 are held movable in thedirection of the diameter of the mold by the tongues 6 which extendoutwardly from .the lower surface at the center of each section, and liein diametric ways 7 formed in the upper surface at the periphery of thebase plate 1 of the mold: Said tongues extend under and lie in contactwith the under surface of the ring 3 .and are provided with upwardly,passing freely through slots 9 that are formed through the body of thering 3 and lie parallel with the "engaging surfaces of the shoulders 4and 4 of the rings 3 and 5-, as clearly shown in Figs. 1, 3 and 4.

Extending from the periphery of the ring 3 through the apertures 10-formed in the flange 2 ,at. opposite. sides of the mold are stems 11having apertures 12 formed in the ends thereof to permit the insertionof bars (one of which is shown by dotted lines in pins 8 which extendThe sections '5 comprising the inner ring are equal in thickness to thewidth of the tread surface of the casing and are concaved to conform tothe arc of the tread, while the circumference of the combined sectionswhen abuttin each other is equal to the circumference o :the tread ofthe casing. Formed in the concaved faces of the sec-' tions 5 are aseries of pockets 15 of such formation as to give the desired grip ingsurface to the tread, and extending rom said pockets horizontallythroughthe body of the sections 5, are vent apertures 16 thatcommunicate with recesses 17 formed in the 'outer faces of the shoulders4 ofsaid sections, as indicated by dotted lines in Figa l and incross-section in Fig. 4:. 1

Formed in the under surfaces "of the top plate 18 and the base platelare annular concavities 19 which coincide with the concavi ties formed,in the faces of the sections 5 and form the radius of the outer arc ofthe tire casing. The inner are of the casing is sustained upon the ringor core 20 which lies concentric with and is confined between the baseand top plates of the mold, as clearly shown in Figs. 3 and 4.

It will be seen from the description of the foregoing construction thatthe operation of the mold in the treatment of the casing is as' follows:The parts of the mold being opened or expanded. as'shown in vFig. 3, I

- are in position to receive the work. The

went resistance to the rub wing and conforming to'the walls of thepocksliown in Fig. 3', when the work may be casing to be treated is laidupon the core 20, the tread surface of the casing'being builtup with asufficient depth of rubber to receive the imprint of the engagingsurfaces of the mold. The core-is then placed in the mold and the topplate of the mold placed in position, as shown in Fig. 2. A bar or leveris then inserted in the aperture 12 and the ring 3 is rotated to theposition 1 shown in Fig. 1.- As said ring is rotated the moved and thecasing stripped off. from the pocket, depression or recess as may bere-- qulred to secure the desired effect of formation upon the tread ofthe casing.

Having thus fully set forth my invention, what I claim as new, anddesire to secure by Letters Patent, is-

1. An expanding and contracting mold comprising a base plate, a.rotatable ring mounted on said base plate, a'nd having internaleccentric shoulders, a segmental ring concentric within saidrotatable'i'ing and having peripheral contact with said eccentricshoulders, a core ringconcentrically within said segmental ring, a topplate for inclosing said parts, means for holding said rotatable andsaid segmental rings in contact and means for actuating said rotatablering to contract said segmental ring toward said core.

2. An'expanding and contracting mold comprising a circular flanged baseplate, a rotatable ring concentric Within the flange of said base plate,and: having internal eccentric shoulders, a segmental ring-alsoconcentric with said base plate and having sliding engagement with theeccentric shoulders of said rotatable ring, acore ring concentricallywithin said segmental ring, a top plate for inclosing said parts, meansfor guiding thesegments of said segmental ring in the direction of thediameter of said mold,

3. An expanding and contracting mold' comp'rising a circular flangedbaseaplate havingdiametric ways formed in the face shoulders 4 engagingthe shoulders 4' of the thereof, a rotatable ring concentric withsections 5 act as wedges to force the sections-'- 5 in the direction ofthe diameterof "the."

the tread of the casing, whereby the 'pla's'tic surface will be forcedinto the apertures or pockets of the sections forming the inner ring,while the air contained within the pockets of the mold will haveaccess'to escape-through the vent a%ertures 16 to preer in freelyenterets. The mold thus closed is placed under 7 suitable pressure andsubjected to heat treatment to set or cure the work while underpressure. The casing when. cured may be readily removed from the-mold byrotating the'ring 3 in a reverse direction to that described, whenthepins 8 "engaging in the slots 9 will cause the sections 5 to bewithdrawn from the tread of the casing, as re of said rotatable.ring-and having project-- ing tongues adapted to seat in the ways ofsaid base plate, a core ring within said segmental ring, a top plate forinclosing said parts, and means extending through the flange of saidbase; plate for actuating said rotatable ring.

4. An expanding and contracting mold comprising a circular flanged baseplate, having .diametric ways formed in the face thereof and havingapertures formed through the flange thereof, a rotatable ring having aseries of curved eccentric shoulders formed in the inner arc thereof andhaving apertured stems on the periphery thereof lying within theapertures of said flange, curved slots formed through'the body of saidrotatable ring parallel with the eccentric shoulders thereon, acontracting ring comprising sections having curved eccentric shoulderscoinciding with the shoulders of said rotatable ring, tongues projectingfrom each of said sections intosaid diametric ways and extending undersaid rotatable ring, pins 10 projecting from said tongues and passingfreely through the curved slots in said 10 tatable ring, a core ringwithin the mold, plates bridging the apertures in said flange anda topplate for inclosing said parts.-

l n testimony whereof, l[\ sign this speci- 15 fication in the presenceof t vo Witnesses.

ALEXANDER W. FINLAYSON. lVitnesses:

B. 1*. WHEELER, M. E. BROESAMLE.

